Synthesis of Trisubstituted Alkenes via Direct Oxidative Arene–Alkene Coupling

Nickel-Catalyzed Hydroarylation of Alkynes under Reductive Conditions with Aryl Bromides and Water

An operationally simple nickel-catalyzed hydroarylation reaction for alkynes is described. This three-component coupling reaction utilizes commercially available alkynes and aryl bromides, along with water and Zn. An air-stable and easily synthesized Ni(II) precatalyst is the only entity used in the reaction that is not commercially available. This reductive cross-coupling reaction displays a fairly unusual anti selectivity when aryl bromides with ortho substituents are used. In addition to optimization data and a preliminary substrate scope, complementary experiments including deuterium labeling studies are used to provide a tentative catalytic mechanism. We believe this report should inspire and inform other Ni-catalyzed carbofunctionalization reactions.

Traceless directing group mediated branched selective alkenylation of unbiased arenes

–COOH group assisted branched selective olefination of simple arenes.

Preparation of tetrasubstituted olefins using mono or double aerobic direct C-H functionalization strategies: importance of steric effects

A novel protocol for the synthesis of tetrasubstituted olefins through a biomimetic approach has been explored. Both mono- and diarylations were performed under ambient oxygen pressure, giving a range of highly hindered tetrasubstituted alkenes. For diarylation of disubstituted substrates, it was demonstrated that the second arylation is the rate-limiting step of the overall transformation.

Palladium(ii)-catalyzed intermolecular oxidative C-3 alkenylations of imidazo[1,2-a]pyridines by substrate-contolled regioselective C–H functionalization

An efficient and highly regioselective palladium(ii)-catalyzed oxidative C-3 alkenylation of imidazo[1,2-a]pyridines with acrylate, acrylonitrile, or vinylarenes has been developed by using oxygen as an oxidant.